Made a few tweaks (CPU, MOBO, RAM). I changed the case because the motherboard has USB 3.0, it seemed a waste not to make the best use of it, the NZXT one did not have front panel USB 3.0.
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($109.99 @ Newegg)
Motherboard: MSI 760GMA-P34(FX) Micro ATX AM3+ Motherboard ($63.98 @ SuperBiiz)
Memory: G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1600 Memory ($74.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($56.98 @ OutletPC)
Video Card: MSI Radeon R9 270 2GB TWIN FROZR Video Card ($174.99 @ SuperBiiz)
Case: Fractal Design Core 1000 USB 3.0 MicroATX Mid Tower Case ($39.99 @ Micro Center)
Power Supply: Rosewill Hive 550W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.99 @ NCIX US)
Total: $660.90